My second season of Caterham Racing in the 2018 Roadsport Championship. Including the build of my first Caterham the awesome R500 Duratec, and the Academy Car in 2017.

Saturday, 2 August 2014

Raceco Exhaust Fitting, Noise Tests and My First Breakdown

Last night we went to the dog racing at Henlow Dog Racing Stadium, so had a few beers, a bite to eat and a couple of lousy bets... Ended up being a bit of a late one so I woke with a reasonably thick head this morning... Went for an early coffee and bacon sandwich to soak up any remaining alcohol and to give me some energy to get the Raceco exhaust fitted and to prep the car for the upcoming track day at Snetterton (weather permitting).

First job was to remove the standard R500 silencer. Real easy to do, loosen the nuts on the bobbin and then loosen the clamp and wiggle it off.

R500 standard exhaust.

Next up, removal of the springs holding the manifold pipes to the catalytic converter and exhaust collector. For those of you who struggle with this, the best solution is to use a decent set of locking pliers to grip one end of the spring wire, then pull it over the hook on the right of the picture below (if you do it the other way the hook is a little longer so makes it very hard). Or you can compress the spring using tie wraps (also works very well).

Springs holding catalytic converter and collector to manifold.

In the picture below you can see the cat ready for removal, complete with guard - it's worth unscrewing the lambda sensor from the cat before you remove it as you may accidentally pull on the connection wires too hard.

R500 catalytic converter and exhaust collector ready for removal.

Catalytic converter removed, lambda probe on left of shot and the springs top right.

Seeing as I was going to be fitting a cat bypass pipe, I thought it'd be worth seeing how much 'lightness' I'm adding, so weighed the cat - it came in at 3.3kg which is quite a lot more than I thought it'd be. Naturally it'd be lighter somewhat without the guard in place.

Caterham R500 catalytic converter being weighed in at 3.3kg

So immediately I wanted to cross check this against the weight of the standard length cat bypass pipe - I say standard length, as it will require cutting to enable the Raceco exhaust to fit. It weighed in at 1.49kg which is a big saving of around 1.8kg.

Next job was to fit the cat bypass pipe, as I was doing noise tests using a decibel meter, I thought it best to try all the configurations possible. When fitting the cat bypass pipe or the cat to the four manifold pipes I find it easier to loosen off the bolts that secure the primary pipes to the engine. this gives a lot more freedom of movement when trying to refit the collector part of the cat (or bypass) pipes. just be sure to retighten them to 34nm as per the manual.

Then it's just a case of putting the collector end onto the manifold pipes, connecting the lambda probe and tightening it, then fitting the springs.

Cat bypass pipe fitted to Caterham R500 Duratec.

So then it was on with the standard exhaust and to test the different noise output that having the cat bypass in place would give. You'll see the bypass pipe is much brighter than the silencer and the primary pipes, but that'll begin to yellow with a few heat cycles to match.

With the standard silencer removed, it was time to line up the Raceco can and mark up the cat bypass pipe ready to mark for cutting. Mike at Raceco suggested to take caution when cutting the cat bypass pipe and to cut less off than you mark initially, as a number of his previous customers have cut a little too much off exposing the gaps at the connection.

Caterham R500 Cat Bypass Pipe marked up ready for cutting.

Got the Dremel out to start the cut, then finished off with a hacksaw.

Cutting the Cat Bypass Pipe with my Dremel.

With a good 10cm cut of the cat bypass pipe, I de-burred the edges, fitted the pipe and then offered it up to the Raceco exhaust.

Cat bypass pipe cut, after first cut, de-burred and fitted.

It turns out I'd been a little too cautious with my cutting and needed to remove an additional 3cm - so back out with the Dremel and in total cut off around 13cm.

Cutting another 3cm off the cat bypass pipe with my Dremel.

With around 13cm of tubing removed from the cat bypass pipe I thought it best to check what it weighed now... Now 1.1kg instead of the original 1.4kg - which is another 300g shaved off the car.

Cut cat bypass pipe, now weighing in at 1.1kg

So I de-burred the car bypass pipe (again), fitted it (again) and offered up the Raceco can... Now the fit was absolutely perfect and it was time to fit. Before I fitted the Raceco silencer I thought I'd take a look inside and took this picture.

The inside of a brand new R500 Duratec Raceco Titanium Exhaust.

I then fitted the Raceco can - wow it looks big! The header pipes are a little yellower than the cat bypass pipe and new silencer, but I think after a few heat cycles everything should be looking that nice 'used' colour.

So my old setup of the Pipercross air filter, catalytic converter and R500 standard silencer weighed 9.4kg and the new (track day) configuration now weighs in at 7.7kg - so that's a 1.7kg saving. I think I'll order myself another cat bypass pipe and run that with the standard exhaust and pipercross air filter for road use as not only will it sound amazing, it'll also be 7.3kg which is 2.1kg lighter (all due to the cat!)

The Noise Reduction
A couple of days ago I went to Maplin and bought a cheap decibel monitor to measure the results of each possible configuration of the air filters, collector and silencer pipes. Turns out I spent about 2 hours recording video of startups, 5,000RPM revs (as this is the 2/3rds region for testing at track days) and fettling with the different setups to find out that Maplins' decibel monitor was absolutely rubbish.

So I decided to go for a blat instead, and remembering there were some nice tunnel noises on a blat I done on Wednesday, I went back to get some footage to compare the two setups. The setups were:-
1. R500 standard exhaust, catalytic converter and pipercross air filter
2. Raceco titanium silencer, cat bypass pipe and carbon track day air box
There's definitely a different tone between the two, and I prefer the sound of the standard exhaust - but that's ok as the Raceco (for me) is purely to ensure I get through the noise tests at track days.

The breakdown

A few days ago I noticed that one of the indicators on the cycle wings wasn't flashing brightly, and made the following video:-

After speaking to Simon at CC Midlands about the issue he said that it was due to a grounding issue, and I just needed to slightly turn the nut connecting the brake hose to the front calliper. (See picture below)

AP racing front calliper on Caterham R500.

So I put the indicators on, tightened the nut very slightly and it worked! Another job done!

So why have I written about the indicator repeater under the 'breakdown' heading... The video below is of the breakdown and should reveal all...

It turns out that the grounding issue is causing a short in the electrics - and when I hit the indicator button at 13 seconds (yes 13 believe it or not) in the video it shorted the electrics and blew the 10 amp fuse. So the job isn't done at all, now I've got to try and work out where the short is.

Here is a picture of the fuse that blew:-

Blown 10 amp fuse.

And a picture of the fuse box with the fuse removed ready for replacement:-

Great Blog,.. quick question did your standard silencer set up fail on track days?, what sort of results did you get is any on static/drive by readings?. With the Raceco silencer how did you get on on the statc test?....

With the Raceco can, no cat, and carbon airbox it tests static at 99.5db (5,500rpm)... Which is fine for use even at Bedford Autodrome, however later on at Bedford when following a 991 GT3 we all got black flagged for noise - as we were running so close together for a long time (drive-by limit is 87.5db there if I remember correctly). More info is on this page of my blog:-http://www.caterhamr500.co.uk/2014/08/bedford-autodrome-track-day.html

I'll also be going to Cadwell Park this coming Monday (25th May 2015). Cadwell Park has a 105db static test limit, so will hopefully get through with the standard exhaust and pipercross air filter! I'll take the Raceco parts just in case though!